This invention relates to a process for the absorption of sulfur compounds, especially H.sub.2 S, from hydrocarbon- and/or C0.sub.2 -containing gases by scrubbing with a physical solvent, and then regenerating and reusing the solvent.
A process step frequently necessary in the processing of raw gas streams is the separation of sulfide compounds, e.g., H.sub.2 S, COS, CS.sub.2, and mercaptans as well as metallic sulfides in some cases. Among these impurities, which generally must be kept away from downstream stages due to their corrosive and catalyst-damaging properties or for other reasons, H.sub.2 S is found most frequently in such gas streams and is generally the predominant impurity.
Examples of gaseous streams that require sulfide compound removal include but are not limited to natural gases, refinery gases, coke oven gases, gases from coal refining, and hydrogen-containing gaseous mixtures. The sulfide compounds are separated from these gaseous streams preferably by a gas scrubbing step with, in particular, a physical solvent (for additional details, see "Erdoel- Kohle-Erdgas-Petrochemie vereinigt mit Brennstoffchemie" [Petroleum-Coal-Natural Gas-Petrochemistry Combined with Fuel Chemistry] vol. 35, issue 8, Aug. 1982, pp. 380-385), incorporated by reference herein. The absorbents employed in that process dissolve the sulfur compounds without chemical reaction and can be desorbed of these sulfur compounds by expansion and/or stripping.
In the absorption of, for example, H.sub.2 S, and subsequent thermal regeneration, the resultant H.sub.2 S from the regeneration is generally reacted to sulfur in a Claus plant provided with a tail gas purification system, thus entailing a high expenditure in apparatus.